1. The Field of the Invention
The present disclosure relates generally to prostheses, and more particularly, but not necessarily entirely, to knee prostheses having adjustable modular components.
2. Description of Related Art
Joint prostheses having modular components are known for use in repairing damaged or diseased knee joints. A knee joint is primarily formed by two bones, namely an upper bone or femur and a lower bone or tibia. Knee joint prostheses typically include a femoral component configured and arranged for insertion into a canal of the femur and a tibial component configured and arranged for insertion into a canal of the tibia. The femoral component may be attached to a stem that may be received into the femur of a patient to improve the stability of the prosthesis. The modular features of the prosthesis allow different sized or configured portions of the prosthesis to be used so that the prosthesis can be properly placed in patients having bones of different sizes and anatomical variations. For example, an anatomic axis may be defined by the axis of the femur, and a mechanical axis may extend from the center of the condyles in the femoral component up through the hip. A valgus angle may be formed between the anatomic axis and the mechanical axis. The valgus angle may be different for different people, for example, ranging between about 5 degrees and about 10 degrees. By providing a modular prosthesis, different stems may be attached to the femoral component at different locations to accommodate different valgus angles.
Moreover, the modularity of the prostheses may allow a reduction of prostheses inventory in that certain components of the prostheses may be used for numerous patients of various sizes and anatomical variations, and only particular portions of the prostheses may need to be selected to properly fit an individual patient.
A drawback of the known modular prostheses is that the adjustment capabilities of the modular components may be limited. The modular components may be fixed to the prostheses in a finite number of locations or orientations. Thus, if a particular anatomical structure does not conform to the possible configurations of the particular prosthesis, a precise fit of the prosthesis cannot be achieved. Moreover, modular prostheses often have complex attaching mechanisms that make assembling the prostheses difficult and time consuming.
The prior art is thus characterized by several disadvantages that are addressed by the present disclosure. The present disclosure minimizes, and in some aspects eliminates, the above-mentioned failures, and other problems, by utilizing the methods and structural features described herein.
The features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the disclosure without undue experimentation. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.